1. Field of the Invention
The present invention generally relates to a transmission lock for an all-terrain vehicle. More particularly, the present invention relates to a transmission lock for use in an engine having a centrifugal clutch.
2. Related Art
All terrain vehicles are powered by internal combustion engines through appropriate drive trains connected to at least one of the wheels. In some such vehicles, the drive train may include a v-belt variable speed transmission that is coupled to a shiftable gear box. The output from the gear box of such drive trains provides rotational power to drive shafts that power the front and/or rear wheels of the vehicle. The gear box in some vehicles enables an operator to select between a high gear and a low gear while the vehicle is at rest. In such shiftable transmissions, the high gear may be used for general riding and high speed operation while the low gear may be used for towing or other high power operations.
Such all terrain vehicles may also include a parking brake. The parking brake generally is structured to utilize the calipers of the disk brake system to clamp and hold a set of brake pads in contact with the brake disk to prevent movement of the wheels. Thus, the brake pads are applied to the disk and locked in the applied position to reduce the likelihood of the vehicle rolling while the engine is disengaged or stopped. When motion is resumed, an operator may forget to disengage the parking brake and may operate the vehicle with the brake pads engaged with the brake disk. Such dragging of the pads on the disk may result in damage, such as glazing of the pads or scoring or warping of the brake disk.
Accordingly, one feature of the present invention is a locking transmission that enables an operator to apply a parking brake without utilizing the conventional braking system of the all terrain vehicle. Another feature of the present invention utilizes a shiftable transmission to engage the drive shafts, and ultimately, the wheels to result in a parking brake that stops wheel motion through disabling drive shaft motion.
One aspect of the present invention, therefore, involves an all terrain vehicle comprising a frame, at least one front wheel and at least one rear wheel connected to the frame and an engine mounted to the frame. The engine powers a crankshaft. A centrifugal clutch connects the crankshaft to a variable speed transmission. A shiftable transmission is connected to the variable speed transmission and at least one drive line extending to at least one of the front wheel or the rear wheel. The shiftable transmission comprises a locking portion capable of locking the transmission from rotation when the locking portion is engaged.
Another aspect of the present invention involves an all terrain vehicle comprising a frame, a seat attached to the frame, and at least one front wheel and one rear wheel connected to the frame. An engine is mounted to the frame generally between the front wheel and the rear wheel with a transmission connected to the engine and connected to at least one of the front wheel and rear wheel. The transmission comprising a variable speed transmission and a shiftable geared transmission contained at least partially within a housing. A parking brake arranged within the housing.